Improved drilling-machine



inted time @tutti dimite.-

WILLIAM C. ,WI-IIPILE, OF NEW HAVEN. CONNECTICUT.

Letters .Patent No. 92,682, dated July 13, 1869.

To all whom 'ltmay concern.:

Be it lrnown that I, WILLIAM C. WHIPBLE, of New Haven, in the countyof` New Haven, and State of Gonnecticut, have invented a new Improvement in Drillv ing-Machine; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and whichsaid drawings constitute part of this specification, and represent, in

Figure 1, a top view;

Figure 2, aside view;

Figure 3, an end view;

Figure 4, a sectional view on linea, z,- and in Figure 5, a detached View, for the illustration of' the invention.

This invention relates to an improvement in drillingmachines 5 `the object being to make the feed automatic,

and, at the same time, to arrest the feed when the drill has advanced the required distance.-

To enable others skilled in the art to construct and use my improvementI will' proceed to describe the same, as illustrated iu the accompanying drawings.

A is the base cubed-plate, supporting, in bearings B, a'inandrel, C, which is caused to revolve by the application of power through a band on the pulley D, which is fixed to the mandrel;

The end, (l, of' the mandrel is fitted to receive thel drill, and the maiuh-el constructed so as to pass longitudinally through the bearings.

E is a pulley, loose upon the mandrel, but of 'a diameter slightly larger than the pulley D, and has fixed to it an open nut, a a, (see fig.'4,) the nut being upon the end ofthe two spring-amis e. (See figs. 1 and 2.)

A portion of' the mandrel, forward of` the pulley E, is threaded, as seen in 1, so that when the nut is closed, as in fig. 4, the thread on the mandrel will work in the thread of the nut.

The nut is closed by clamping-levers Il F, and when clamped, is held by a latch, H, as seen in figs. 3 and 4, and by freeing the latch, the jaws and nut open, as seen in fig. 5.

The nut being closed upon the thread, if the two pulleys were caused to revolve at the same velocity,

there would be no advance or action of' the thread on the mandrel Whatever, the nut revolving with the mandrel as if a part of it; but if the pulley D be driven, and the pulley E stationary, then the mandrel would advance, in accordance with the cut of the thread on the mandrel, but the pulley E, revolving slower than the pulley D, reduces the advance of the spindle, by the action of the thread, `in proportion as the revolution of thepulley E is slower than the pulley D; and,l

further, if the pulley E revolved more rapidly than the pulley D, then the mandrel would be retracted.

The great advantage of this construction lies in this, that if .in boring and feeding by the differential pulleys, at any time, the pressure should become so great as to arrest the movement of the drill, the pulley lil would continue to revolve, and consequently draw back or ease up on the mandrel until the drill would again -advance; hence, the. nut combined with the pulley E, of' a less velocity than the pulley D, makes, the feed selfadjustable and automatic, confoimng the feed to the nature of the material being bored.

When the dlill has entered or bored the required distance, itis desirable to arrest its further advance; I therefore arrange, in -connection with the `mandrel C, a sliding rod, L, which has upon it an adjustable trip, P, which, being set'upon the'rod, willstrike the latch H, when drawn sufficientlyfar, and disconnect the jaws F F, so as to f'ree the nut from the thread of the maudrel, then a spring or rod, L, will throw back the mandrel.

Having fully described my invention,

VVhatI claim as new and useful, and desire to secure by Letters Datent, is-

1. In combination with thethreaded mandrel C and its fixed pulley D, the open nut a, and its pulley E, of' alarger diameter than the pulley D, so as to operate substantially as set forth.

2. In combination with the above, the sliding rodI.

with its trip P, so as to operate the llatch H, substantially as set forth.

IVM. CWHIPPLE. Witnesses:

A. J TIBBITs, J. H. SHUMWAY. 

